1. Field of the Disclosure
This disclosure relates to an auto probe device, and more particularly, to an auto probe device which can reduce a defect generation rate in the lighting test of a liquid crystal panel while improving accuracy, and a method of testing a liquid crystal panel using the auto probe device.
2. Description of the Related Art
Liquid crystal display (LCD) devices are quickly replacing cathode ray tubes (CRTs) in many applied fields because the LCD devices can be made compact and mass productivity thereof may be improved. In particular, the LCD device of an active matrix type driving liquid crystal cells using thin film transistors (TFTs) exhibits a superior image quality and low power consumption. With recently developed mass-production technologies, the LCD devices having large screens and high resolutions are rapidly developed.
A process to manufacture active matrix type LCD devices includes substrate cleaning process, a substrate patterning process, an orientation layer forming/rubbing process, a substrate combining/liquid crystal injection process, a mounting process, a test process, and a repair process.
The test process includes an electric lighting test and a pixel defect test which are performed after a variety of signal lines and pixel electrodes are formed in the liquid crystal panel. In the process of testing a liquid crystal panel, a lighting test using an auto probe device is performed for a test to check the existence of a point defect and a breaking down of the signal lines in the liquid crystal panel.
The auto-probe device includes a gate pad formed on the liquid crystal panel to test a defect of the signal lines of the liquid crystal panel, a main body for applying a signal to a data pad and a common electrode pad, and a plurality of needles connected to the main body and directly contacting the gate pad, the data pad, and the common electrode pad.
The defect test of a liquid crystal panel is performed by allowing the needles of the auto-probe device to have one-to-one contacts with the pads, that is, the gate pads, the data pads, and the common electrode pads, formed on the liquid crystal panel. Since allowing the pads of the liquid crystal panel to have one-to-one contacts with the needles of the auto probe device is not easy, contact miss may be generated during the contact process.
To address the above matter, there is a method in which a shorting bar connected to a plurality of pads is provided in a non-display area of the liquid crystal panel to allow the shorting bar and the needles of the auto probe device to have one-to-one contact with each other. In this case, the contact miss may be reduced when the shorting bar contacts the needles of the auto probe device, compared to the above-described method. However, when a part of the non-display area of the liquid crystal panel where the shorting bar is formed is torn off, signals may not be applied to the signal lines of the liquid crystal panel so that a test defect may be generated.